Apparatus for the inhalation of gases



June 24, 1958 M. A. LOREDO SERRA 2,840,074

APPARATUS FOR THE INHALATION OF GASES Filed May 12. 1955 MA. LOREDO SERRA INVENTOR.

- 2,840,074 1C6 Patented June 24, 19 58 2,840,074 APPARATUS jFoR THE INHALATION OF GASES Miguel Angel Loredo Serra, Havana, Cuba Application May 12, 1955, Serial No. 507,936

Claims priority, application Cuba -May 24, 1954 3 Claims. (Cl. 128-188) The present "invention relates to an improved apparatus for the administration of no-efiort anesthesia and for controlled or forced breathing of gases under pressure.

The apparatus of this invention is an improvement over the apparatus described in my U. S. Patents Nos. 2,593,774 and 2,677,371.

The object of the apparatus according to the invention is to provide a new type ofb'reathing 'bag'which permits the bag to instantaneously adjust' itself to the breathing eiforts of the user. It also comprises means for the control'of forced breathing.

For the attainment 'of the aforementioned object the invention includes the elements and an arrangement of the same which will presently be described in connection with-the annexed drawings, in which:

Figure 1 is a perspective view, with some parts broken their tubular form at all times in order to allow the gas or gases to flow freely through them, while bellows B by their ability to expand and contract, permit the tubular breathing bag to instantaneously adapt itself to the breathing efforts of the user, supplying him with the required amount of gas or gases when he inhales and easily accommodating the gases expelled by the user when exhaling. This is done with a minimum of fluctuation of the pressure within the circuit. The interior of bellows B communicates with the external atmosphere through opening B in the wall of tubular member 'B.

Referring to Figures 2, 3 and 4, the rigid tubular body B has an elongated opening or slot B over which a wire mesh (or perforated plate) B is attached to the outer surface of rigid body B for preventing bellows B from being extruded through opening B when the pressure of the gases within the circuit is substantially increased. The use of slot B and of mesh B is optional and, if desired, they may be replaced by a longitudinal series of small perforations in the wall of rigid tubular member B. The bellows extends longitudinally within tube B immediately below slot B the upper edges of said bellows secured to the edges of slot B and being so attached to the wall of tube B that the union between them 'is absolutely fluid "tight to prevent the gases in the circuit 1 from escaping to the outer atmosphere 'andthe atmosaway and others shown in "section, illustrating the improved apparatus and circuitof the invention.

Figure Z is a side elevation view of one of the tubular sections of the new breathing bag, the section being illustrated with a flexible connector attached to each of its ends.

Fig'u'reZ.

Figure 4 is aview similar to Figure 2 but with part of the rigid tubular body brokenaway to better-illustrate the union of bellows located within the"t'ubular element,-and'the'rigid'tubular body. 9

Hereafter, in both the specification and claims, the term tubular breathing bag will be used to designate the new breathingbag as a whole and said designation will include all the parts er theb'ag, such as the rigid tubular elements, small bellows, flexible connectors, etc. which when duly united constitute said new breathing bag.

Referring to Figure 1 of the drawing, the tubular breathing bag according to the invention comprises a series of relatively short tubular rigid members -B joined end to end "by short and flexible connectors C, which in the case illustrated consist of short lengths of corrugated rubber tubing which impart to the breathing bag the necessary flexibility for easy manipulation by the operator. The breathing passage or opening -'of the tubular breathing bag is located at A intermediate "the ends of 'a specially shaped hollow member A connected across the ends of the tubular breathing bag, but member Amay have any "suitable shape, andmay be located at some other point of the tubular breathing'bag provided it lies between the inlet'and the'outlet of'thetubular bag, that is, between the ends of the same. Since the 'only purpose of the lengths 'of-rubbertubingC is to establish, a flexible connection between adjacent rigid tubes B, any other connectors may be used, provided they impart to saidjoints therequired flexibility.

Tubular elements '13 constitute one of the essential parts of the tubular breathing-bag, and as previously stated,

they are made from rigid material in-o'rder toxpreserve Figure 3 is a cross section of the tubular section of pheric air from enteringand mixing with the gas or gases in the circuit. In the drawing the upper edges of the bellows are shown attached to the inner surface of tube B but, if so desired, they may be brought out through slot B and then attachedto the outer surface of tube B.

Bellows B projects radially into tube B a predetermined distance, and are such that when normally expanded otter the least, possible resistance to the flow of the gases through the tube, the bellows being fully ex tended when the pressure within the circuit is substantially equal tothat of theexternal atmosphere. The bellows is of suflicient flexibility to respond immediately to the smallest variation in pressure that may occur within the circuit. Any increase in the pressure of the gases within the circuit produces a proportionate contraction of the bellows until, when said pressure reaches a'predet-ermined value, bellows B is completely flattened against the inner surface of tube; B, this being the position occupied by bellows B Whenthe apparatus isfused in the administration of forced respiration.

Due to the improvement produced in the circuit by the tubular breathing bag the apparatus may now be used, not only in the administration of no-efrort inhalation anesthesia, but also forc'ontrolled or forced breathing-and whenever the use of gases under pressure is necessary or convenient. With forced or controlled breathing it is very convenient to include in the circuit some means for controlling the pressure of the gases as desired.

In'Figure 1 of the drawing is shown one of the means which may be used for this purpose. It consists of a flexible bag 'E, made of flexible material like rubber, in communication with the circuit through which the gases how, and furnished with a discharge valve P which, when open, connects the bag E with the atmosphere. Normally this valve is kept closed, being opened only when it is desired to discharge some of the gases from the circuit, for example, when after having used the apparatus to applyforced respiration'it is desired reuse it in the administration of no-effort inhalation anesthesia.

In order -to clearly illustrate the function performed by bag E, the case in which the apparatus is used for controlled breathing will be considered. In this case suifici'ent oxygen is introduced into the circuit by open- :ing the-corresponding valve of the oxygensupply source K until sufficient oxygen has been introduced into-the circuit to raise the pressure in the circuit to the required value. When this is done, all the bellows B are flattened against the inner surface of the rigid tubes B in which they are mounted. Now, since the problem of producing controlled breathing cannot 'be solved by simply increasing the pressureof the gas supplied to the user, it is obvious that in order to obtain the rhythmic fluctuation in the pressure of the gas necessary for the successful application of controlled breathing, the circuit must-be supplied with a suitable device easily manipulated by the anesthetist, and such a device is bag E. Thi bag being connected to the circuit is filled by the oxygen circulating in the circuit and the operator by successlvely pressing and releasing bag E causes the necessary fluctuations in the pressure of the gas applied to the patient to induce the required controlled breathing. When the operator compresses bag E in the required manner, a predetermined amount of oxygen is. forced from the bag into the circuit thereby increasing the pressure in the latter, and when he frees .bag Efrom said external pressure the bag expands and retakes from the circuit an equivalent amount of thegas. This rhythmic increasing and decreasing of the pressure within the circuit forces .into and withdraws from the lungs of the patient the amount of gas required forthe establishment of the so-calledcontrolled breathing. 1

wards the tubular breathing bag.

From the above it is obvious that bag E is not a.

breathing bag, but acts simply as a reservoir wherein a It is also obvious that it is not essential that reservoir E be a bag. It may have the form of a bellows with a single opening, or any other flexible gas containing device capable of expelling a portion of the gas contained therein when it is compressed and capable of recovering from the circuit an equivalent amount of gas when the applied pressure ceases.

The invention also comprises another improvement which is also important for the correct working of the apparatus. i i I In the circuit of the apparatus are two bellows pumps which act'alternately to maintain a substantially uniform and continuous current of gases passing through a corresponding canister containing a carbon dioxide absorbing substance. By means of a suitable arrangement of valves each impeller forces the gases through its canister first in one direction and then in the opposite direction.

Referring toFigure 1 vof the drawing, it is seen that the gas circulating and purifying device of the present invention comprises. two separate bellows pumps Y and Y each one having a single opening located at its upper end and each being in direct communication with the interior of a canister H and H respectively, which canisters contain a carbon dioxide absorbing material. Both canisters are included in the circuit and each of them communicates with." the portion of the circuit through which the impure gases coming from the tubular breathing bag circulate, the communication in each instance being controlled by. an inlet valve G, one for each canister, which opens to allow impure gases to penetrate which opens and allows the purified gas to pass'into that "portion of the circuit through which the gases flow to- As soon as the bellows ceases to disthe gas within the canister and then to outlet valve G 4 l The pumps work alternately, so that when one is performing its suction stroke the other is performing its compression stroke, whereby a substantially continuous stream of purified gas is being discharged towards the tubular breathing bag. This can be seen in Figure l. The mechanism employed to move the pumps does not form part of the invention and, therefore, the one illustrated should not be construed as limiting the invention since it is obvious that many known mechanisms may be employed to drive the pumps alternately. Since both combinations of pump and canister are identical, it is deemed that the above description is sufiicient to give a clear idea of the manner in which both work.

From the above it is seen that the new system employed in the circulation and purification of the gases in the circuit is entirely different and more efiicient than those heretofore in use, not because it contains two canisters instead of one, but because due to the novel arrangement of the inlet and outlet valves, the impure gases are obliged to pass twice through the purifying medium.

In Figure 1 of the drawing the device E, which as stated before is not a breathing bag but simply a reservoir, is illustrated as located in that part of the circuit through which the purified gases flow towards the tubular breathing bag, but it is obvious that said reservoir may be located at any convenient point in the circuit.

Having thus described my invention, what I claim is: V 1. In apparatus for the inhalation of gases comprising a closed circuit from which the outer atmosphere is excluded and within which the gas orgases are forced to circulate in a substantially continuous and uniform cur- :rent by mechanicalmeans included in the circuit, said circuit also including carbon dioxide absorbing means and a 'source of supply of the gas or gases to be inhaled, that improvement comprising a tubular breathingbag in said circuit and consisting of a plurality of rigid and relatively short tubular elements, a plurality of short and flexible connectors connecting said elements in series, each of said rigid tubular elements having a longitudinal portion of its wall perforated, a bellows within each of said rigid tubular member, said belows being open at the top and with its upper edges hermetically attached to said rigid tubular member so that said perforation in said rigid tubular member communicates the interior of the bellows with the external atmosphere, said tubular breathing bag also including a tubular member having a breathing passage located between its ends.

2. The improvement as claimed in claim l in which said circuit also includes a reservoir for the gas or gases circulating in the circuit, said reservoir consisting of a hollow device with flexible walls, having a one way discharge valve.

3. The improvement as claimed in claim 1 and means for passing gases from said circuitthrough said carbon dioxide absorbing means, said carbon dioxide absorbing means being contained in two canisters, said means comprising two alternately acting pumps, each attached to an end of a separate canister containing carbon dioxide absorbing means, a one directional inlet valve connect- .ing the other end of each of said canisters to the porimpure gases into said canister during the suction stroke of said pump, and a one way discharge valve connecting the same endof said canister with the portion of the circuit through which pure gas or gases flow towards the tubular breathing bag, whereby purified gases from said canister are discharged into said portion of the circuit during the discharge stroke of said pump.

References Cited in the file of this patent UNITED STATES PATENTS 2,593,774 Loredo Apr. 22, 1952 

